<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>盒子模型</title>
    <style>
        .box{
            width: 500px;
            height: 300px;
            background-color: orange;
            padding: 20px;
            border: 3px solid #0000ff;
        }
    </style>
</head>
<body>
<h1>盒子模型</h1>
<hr>
<div class="box">
    <ul>
        <li>盒子的相关属性 width height border padding</li>
        <li>hello how do you do yuanyi</li>
        <li>hello1 how do you do yuanyi</li>
    </ul>
</div>
</body>
</html>